The correct fertilization of cucumbers
Under suitable conditions, high-yielding cucumber stocks are expected to produce 200 tonnes per hectare. While the fruit ripens on older parts, the plant continues to grow. Fertilization should therefore support sustained growth and at the same time allow fruit with high market value and good taste to ripen well. The nitrogen supply must be sufficient as long as the growth continues. Phosphorus and large quantities of potassium enable high quality (taste, colour, firmness and shelf life). The provision of enough potassium is essential for fruit formation and fruit enlargement. However, is important to avoid an excess of nitrogen as it increases susceptibility to foliar diseases and fruit rot. Furthermore, too much nitrogen can affect the quality and the fruit can develop a bitter taste.
Cucumbers are very sensitive to chloride. Fertilization with potassium chloride is therefore only possible in autumn before cucumber planting. In the growing season, potassium sulphate is the better choice. Cucumbers are also sensitive to salt. Iron deficiency is best counteracted with leaf fertilization of iron chelate. Splitting the applications is absolutely necessary.
If grown in the field, some fertilizer is spread before laying the mulch film.The rest is fertilized in several doses according to demand, partly only in the row. Calcium should be applied in autumn before planting. Magnesium-emphasised limestones (2,000kg CaO/ha) may be used.
In protected cultivation, fertigated soil or substrate culture is at the cutting edge. On the one hand it is possible to use different fertilizers at different growth phases, on the other hand the nutrient quantities can be adapted according to demand, vegetation progress and harvest quantities.
Yield parameters of cucumbers:
• Number of plants/m²
• Number of fruits/plant
• Fruit weight
The amount of shoots per m² and continuous production of flowers and fruits determine the yield.